This invention relates to an ink jet recording apparatus comprising an ink jet recording head for ejecting ink droplets in response to print data and ink cartridges for each color placed thereon replaceably, and in particular to a management technique of the remained ink amount in each of the ink cartridges.
For example, an ink jet recording apparatus of a serial printing system comprises: an ink jet recording head mounted on a carriage and moving in a main scanning direction; and a paper feeder for transporting recording paper in a subscanning direction orthogonal to the main scanning direction, and ejects ink drops through the recording head based on print data, thereby printing on the recording paper.
In a relatively small-sized recording apparatus intended for home use, ink cartridges for supplying ink to a recording head are detachably placed on a carriage. The recording apparatus comprises a consumed ink amount calculator for counting the consumed amount of ink stored in each ink cartridge, thereby calculating the consumed ink amount in each ink cartridge and when the consumed (counted) amount of ink in any ink cartridge reaches a predetermined value, it is judged that the ink cartridge is an ink end state.
In the recording apparatus, to replace the ink cartridge based on the ink end, the ink cartridge in the ink end state is drawn out from the cartridge holder on the carriage and a new ink cartridge is inserted into the cartridge holder on the carriage.
In this case, in this kind of recording apparatus, hollow ink introduction needles are extended upward in the bottom of the cartridge holder. To place a new ink cartridge, an ink supply port of the ink cartridge is pushed into the ink introduction needle, whereby the ink supply port of the ink cartridge is joined to the ink introduction needle and ink is supplied from the ink cartridge to the recording head mounted on the carriage.
If the ink cartridge is replaced as described above, a problem of air entering through the hollow ink introduction needle and trapping air in the ink introduction needle occurs. A part of the trapped-in air moves into the recording head on the ink flow produced by the print operation, etc., and creates a bottleneck in the normal ink droplet ejection from the recording head, causing a print failure to occur.
Thus, a capping member capable of sealing the nozzle formation face of the recording head is provided and a negative pressure is applied in the capping member by a suction pump, whereby ink is sucked from the recording head and at the same time the air trapped in the ink flow passage is discharged. Such ink suction and discharging operation performed after ink cartridge replacement is called replacement cleaning operation.
By the way, most of the above-described recording apparatus are configured so that black ink, yellow ink, cyan ink, and magenta ink, for example, supplied from the cartridges are ejected through nozzle rows formed on one recording head. When the above-described replacement cleaning operation is executed, one capping member sealing the nozzle formation face sucks a relatively large amount of each color ink.
Therefore, if a first cartridge of one color is in the ink end state and is replaced with a new cartridge and the replacement cleaning operation is executed, a situation in which the ink end state is established as the replacement cleaning is executed can occur in a second cartridge having a small ink amount. Further, if replacement cleaning is again executed as the second cartridge is replaced with a new cartridge, a state in which a third cartridge reaches the ink end state can also occur.
When one color cartridge is replaced and the suction operation is executed, although other cartridges do not reach the ink end, if the print operation is restarted, a state in which as slight print operation is executed, any other cartridge is in the ink end state and must again be replaced with a new cartridge can also occur.
FIGS. 12 to 15 schematically show the situation in which the above-described state can occur, wherein the consumed (counted) amount of ink in each color cartridge is hatched. Therefore, the count indicates the ink end state, the corresponding ink cartridge is assumed to reach the ink end. For example, if black ink is in the ink end state (count A) as shown in FIG. 12, the black ink cartridge is replaced.
As the suction operation is executed when the black ink cartridge is replaced, the consumed (counted) ink amounts of cyan, magenta, and yellow are incremented by cc, mm, and yy, as shown in FIG. 13. As print is executed in this state, when each counter is further incremented by pp accompanying a slight print amount, the yellow ink cartridge reaches the ink end state as shown in FIG. 14.
Then, if the yellow ink cartridge is replaced, the suction operation is again executed and the consumed (counted) ink amounts of black, cyan, and magenta are incremented by bb, cc, and mm accordingly, as shown in FIG. 15. In the state as shown in FIG. 15, if print is further restarted, the magenta ink reaches the ink end state as slight print operation is executed, and again the ink cartridge (in this case, magenta ink cartridge) must be replaced.
Therefore, if the ink consumption situation as described above occurs, the second cartridge must be replaced immediately after the first cartridge is replaced, and after the second cartridge is replaced, it becomes necessary to replace the third cartridge, resulting in rasping the user's nerves. Moreover, the ink suction operation needs to be executed whenever the ink cartridge is replaced, and consequently the ink in each cartridge is wasted.